Re: VLBI and MIRANdA
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From: <r.dodson_at_email.protected>
Date: Fri, 13 Apr 2007 12:59:37 +0200
Steve,
I think getting VLBI capabilities is very important on the WA
instruments. We need to chase 2.4 GHz hard, because whilst the L band
observations are better for the steep sources, with the wider
bandwidth even steep sources are easy targets. I don't see any mention
of bandwidth. Will Gbps and better be possible with the current
design? That is important, and may not be included (as who'd put 512
MHz bandwidth at 300 MHz?).
Comments:
My first response is that it seems very parochial. The references
are (for example) 80% Tingay et al. This is an early draft of course,
and is no doubt caused by lack of input from others. I certainly am
guilty of that. But the science needs to be be opened up greatly. For
example instead of pulsar parallax, talk about "proper motions and
parallaxes, for example of pulsars", likewise OH masers to masers.
I agree with Chris that the focus on the field of view is too strong.
Also there are too many details on the trigger science, which I think
is (almost) irrelevant. Have I missed something? It seems to me that
this does not require anything extra in the design at this point, and
is only a scheduling issue.
_Introduction_
considering -> using
pulsar parallaxes -> proper motions and parallaxes
OH masers -> masers (in this case I am not sure -- what other L-band
masers as observed in VLBI? There are molecular lines, but these
usually resolve.)
This would be a good time to bring in matching resolution. Current
LBA at 6GHz is ~ M+LBA at 2 GHz.
(You could put references to these if you wished. There is a Vela
PSR paper which would fit, and there are Methanol maser papers which
address similar questions. Is there a OH maser LBA paper? On the
subject of references I would chose to put in the VSOP M87 paper,
which draws heavily on the high resolution at low frequencies
(provided by HALCA) to reach conclusions unobtainable by ground based
VLBI. This overlaps with the goals here.)
"some form" -> targeted
"pulsar VLBI" -> astrometry
"interesting science" * 100 -> something else occasionally :)
Rather than extending the frequency up to 2.4GHz to cover Ceduna,
extend up to cover all the (global) geodetic antennae -- including the
new AUSGeo ones.
_Miranda as a component_
pulsars -> astrometry
Are these uv coverages just image dumps from the VRI? There must
be something a bit better. I would use the output from sched, or
fakesat. I can make these for you, but not till next week.
_potential programs_
A section on the science with 2.4 GHz with M+LBA is need. AGNs and
pulsar proper motions are the obvious, as I don't think that there are
any masers in this band.
Add references for observations made with the exsiting LBA with OH
(Jim C?), water (Simon E? Greenhill) & methanol (me) masers. Zeeman
splitting (Simon) has only been done with the ATCA (for reasons we all
know).
OH Masers -> Extra galactic OH masers
pulsar parallaxes -> pulsar parallaxes and proper motions
Add this somewhere
Pulsars, kicked by the SN explosion, have high and easily
detected proper motions. These have been found to lie along the spin
axes, and therefore can be used to provide insights into the initial
blast of the SN and the pulsar characteristics.
The Vela reference could be used if this is a place which
needs references.
comments start to get more sparse after this point.
Chapter XX -- is this a place holder or it is really chapter 20?
This there twice.
on transients "likely" -> "more than likely". They can not be
transient if they are not compact.
I don't think figure 3 adds anything at all.
You have two "finally" paragraphs
The largest survey of Tb from VSOP was Horiuchi etal -- that
should be the reference.
none of the parameters na,nc etc are defined, but really I think
the whole section is too detailed and of little relevance.
all the best,
Richard
PS another comment. Why oh why a word document which is too big for
nearly everything I would use to read it?
Received on 2007-04-13 21:00:06
Date: Fri, 13 Apr 2007 12:59:37 +0200
Steve,
I think getting VLBI capabilities is very important on the WA
instruments. We need to chase 2.4 GHz hard, because whilst the L band
observations are better for the steep sources, with the wider
bandwidth even steep sources are easy targets. I don't see any mention
of bandwidth. Will Gbps and better be possible with the current
design? That is important, and may not be included (as who'd put 512
MHz bandwidth at 300 MHz?).
Comments:
My first response is that it seems very parochial. The references
are (for example) 80% Tingay et al. This is an early draft of course,
and is no doubt caused by lack of input from others. I certainly am
guilty of that. But the science needs to be be opened up greatly. For
example instead of pulsar parallax, talk about "proper motions and
parallaxes, for example of pulsars", likewise OH masers to masers.
I agree with Chris that the focus on the field of view is too strong.
Also there are too many details on the trigger science, which I think
is (almost) irrelevant. Have I missed something? It seems to me that
this does not require anything extra in the design at this point, and
is only a scheduling issue.
_Introduction_
considering -> using
pulsar parallaxes -> proper motions and parallaxes
OH masers -> masers (in this case I am not sure -- what other L-band
masers as observed in VLBI? There are molecular lines, but these
usually resolve.)
This would be a good time to bring in matching resolution. Current
LBA at 6GHz is ~ M+LBA at 2 GHz.
(You could put references to these if you wished. There is a Vela
PSR paper which would fit, and there are Methanol maser papers which
address similar questions. Is there a OH maser LBA paper? On the
subject of references I would chose to put in the VSOP M87 paper,
which draws heavily on the high resolution at low frequencies
(provided by HALCA) to reach conclusions unobtainable by ground based
VLBI. This overlaps with the goals here.)
"some form" -> targeted
"pulsar VLBI" -> astrometry
"interesting science" * 100 -> something else occasionally :)
Rather than extending the frequency up to 2.4GHz to cover Ceduna,
extend up to cover all the (global) geodetic antennae -- including the
new AUSGeo ones.
_Miranda as a component_
pulsars -> astrometry
Are these uv coverages just image dumps from the VRI? There must
be something a bit better. I would use the output from sched, or
fakesat. I can make these for you, but not till next week.
_potential programs_
A section on the science with 2.4 GHz with M+LBA is need. AGNs and
pulsar proper motions are the obvious, as I don't think that there are
any masers in this band.
Add references for observations made with the exsiting LBA with OH
(Jim C?), water (Simon E? Greenhill) & methanol (me) masers. Zeeman
splitting (Simon) has only been done with the ATCA (for reasons we all
know).
OH Masers -> Extra galactic OH masers
pulsar parallaxes -> pulsar parallaxes and proper motions
Add this somewhere
Pulsars, kicked by the SN explosion, have high and easily
detected proper motions. These have been found to lie along the spin
axes, and therefore can be used to provide insights into the initial
blast of the SN and the pulsar characteristics.
The Vela reference could be used if this is a place which
needs references.
comments start to get more sparse after this point.
Chapter XX -- is this a place holder or it is really chapter 20?
This there twice.
on transients "likely" -> "more than likely". They can not be
transient if they are not compact.
I don't think figure 3 adds anything at all.
You have two "finally" paragraphs
The largest survey of Tb from VSOP was Horiuchi etal -- that
should be the reference.
none of the parameters na,nc etc are defined, but really I think
the whole section is too detailed and of little relevance.
all the best,
Richard
PS another comment. Why oh why a word document which is too big for
nearly everything I would use to read it?
Received on 2007-04-13 21:00:06